“The shooting incident in Ferguson, Missouri this weekend deserves a fulsome review. In addition to the local investigation already underway, FBI agents from the St. Louis field office, working together with attorneys from the Justice Department’s Civil Rights Division and U.S. attorney’s office, have opened a concurrent, federal inquiry,” Holder said in a statement Monday. “The federal investigation will supplement, rather than supplant, the inquiry by local authorities. At every step, we will work with the local investigators, who should be prepared to complete a thorough, fair investigation in their own right.”

A large crowd gathers at the candlelight vigil, Sunday evening, Aug. 10, 2014, in Ferguson, Mo. A few thousand people crammed the street where a black man was shot multiple times by a suburban St. Louis police officer. The candlelight vigil Sunday night was for 18-year-old Michael Brown, who died a day earlier. Police say he was unarmed. (AP Photo/St. Louis Post-Dispatch, J.B. Forbes)